Analog multipliers may be used to multiply two analog signals to produce an output, which is effectively the product of the analog signals. In some cases, an analog multiplier may be used to multiply a first analog signal by the inverse of a second analog signal. The output of an analog multiplier may be either a voltage or a current.
Some analog multipliers may use two diodes to generate a current, which is an exponential function of the two input voltages. As a result, any offset voltage from the two input voltages may be exponentially magnified. In addition, the exponential function of the diodes tends to be sensitive to both process variations and temperature variations. As a result, the output of an analog multiplier may vary with process.
These process variations may affect the accuracy of the analog multiplier and lead to poor manufacturing yields or result in the need for post manufacturing calibration.
Accordingly, there is a need for a new analog multiplier circuit or technique that substantially reduces or eliminates the process and batch to batch variations in an output of an analog multiplier.